Performing Billing 
Purpose
You create customer invoices for single and pool contracts within Usage-Based Billing.
The system uses the Billing Engine (BE) to bill the contracts. Billing involves three steps:
...
1. The system provides the billing data in the billing due list of the Billing Engine.
2. You select the relevant billing due list items in the billing due list.
The system creates the necessary billing documents.
3. The system executes all downstream processes, such as posting the accounting documents and updating the source documents.
For more
information on performing billing, refer to 
CRM
Billing.
Prerequisites
· You have carried out pool prebilling before you bill a pool contract.
Process Flow
The following detailed processes are available for billing: